Time reversibility of Navier–Stokes turbulence and its implication for subgrid scale models

Time-reversibility of Navier-Stokes turbulence and its implication for subgrid scale models

Inertial Manifolds for Certain Subgrid-Scale α-Models of Turbulence

In this note we prove the existence of an inertial manifold, i.e., a global invariant, exponentially attracting, finite-dimensional smooth manifold, for two different sub-grid scale α-models of turbulence: the simplified Bardina model and the modified Leray-α model, in two-dimensional space. That is, we show the existence of an exact rule that parameterizes the dynamics of small spatial scales ...

Subgrid-scale modeling for Large-eddy simulations of compressible turbulence

We present two phenonmenological subgrid-scale (SGS) models for large-eddy simulations (LES) of compressible turbulent flows. A nonlinear model and a stretched-vortex model are tested in LES of compressible decaying isotropic turbulence. Results of LES at 32 resolution are compared to corresponding 256 direct numerical simulations (DNS). We use numerical schemes based on compact differences and...

Hot-wire Array for Turbulence Research in Subgrid-scale Modeling

Modeling of turbulence for Large Eddy Simulations (LES) must be based on sound understanding of the relationships between large and small scales. In order to study flows with a large range of active length-scales, high Reynolds number experimental data can be used. Thermal anemometry provides the possibility of acquiring long records of turbulence data, which are necessary for evaluating statis...

A modified-Leray-α subgrid scale model of turbulence

Inspired by the remarkable performance of the Leray-α (and the Navier–Stokes alpha (NS-α), also known as the viscous Camassa–Holm) subgrid scale model of turbulence as a closure model to Reynolds averaged equations (RANS) for flows in turbulent channels and pipes, we introduce in this paper another subgrid scale model of turbulence, the modified Leray-α (ML-α) subgrid scale model of turbulence....